东濮凹陷黄河南地区下第三系沉积体系与油气评价

为了加速东濮凹陷黄河南地区油气勘探的步伐,本文根据现代沉积体系理论,综合运用地质、测井和地震资料,首次在东濮凹陷黄河南地区下第三系中系统地确定了冲积扇、河流、扇三角洲、三角洲—滑塌浊积扇、滩坝、近岸水下扇和轴向重力流水道等7种类型的沉积体系,并描述了这些沉积体系在地质、测井和地震等方面的沉积特征。结合盆地断裂活动特点,指出充填盆地沉积体系的演化具有明显的阶段性,沉积体系的平面展布具有不对称性,从而建立盆地沉积体系演化模式。同时,结合油气勘探实践指出富集油气的有利相带。     

从岩石组合特征分析库-满坳拉谷的发育史

由于地幔柱的作用,新元古代晚期至古生代早期在塔里木板块东北部曾发育一个坳拉谷,称之为库—满坳拉谷。在库鲁克塔格和满加尔凹陷地区,从早震旦世到奥陶纪发育中酸性和基性双峰火山岩建造、深水碳酸盐岩和复理石沉积体系,具坳拉谷盆地沉积特征;志留系—石炭系具有坳陷盆地沉积特征;上石炭统—二叠系缺失;中生代发育陆相沉积体系,标志着强烈造山运动盆地隆起消亡。这些地层层序构成了典型的坳拉谷盆地沉积体系,完整地记录了库—满坳拉谷从产生至消亡的构造发育史。     

扇形沉积体生长的分形几何特征分析

扇形沉积体是我国内陆及沿海地区中、新生代含油气盆地中的重要油气勘探目标,对其平面分布形态和内部结构参数特征的定量表征是油气勘探部门极为关注的问题。随着分形几何理论在沉积学领域应用的日趋广泛,使人们可从新的角度来考虑这一问题的解决方法。扇形沉积体的生长是一个复杂的非线性动力学过程,且具有分形特征。分维数的大小反映了沉积体外部形态和内部结构的复杂程度,分维数的变化幅度预示着构造和沉积背景的某些信息。将分形和混沌理论相结合,也许是实施扇形沉积体非线性动力学建模和模拟的重要途经之一。     

鄂尔多斯盆地东北部延安组铀异常与沉积体系的关系

在鄂尔多斯盆地东北部,延安组第V成因单元存在着多处铀异常,这对铀的后备战略基地建设有重要意义。从沉积学的角度重建了第V成因单元的沉积体系,识别出两种沉积体系,分别是位于研究区西北部的辫状河沉积体系和东南部的曲流河沉积体系。通过对铀异常信息的成功提取及平面编图,发现延安组中铀异常呈一个又一个具有自我中心的单元出现,且与曲流河沉积体系的关系密切:通常发育于河道分岔或转弯处;普遍发育于薄砂带(区),一般砂体厚度在30 m以下,含砂率小于40%;铀异常单元与厚煤层关系密切;主要赋存于粒度较细的岩性中,部分也富集于煤中,但铀异常最高值富集于中砂岩中。     

南海晚新生代地层结构特征、沉积厚度及沉积模式

本文综合地震、钻井及区域地质资料，通过分析地震相参数等，研究南海晚新生代（E3-Q）地层结构特征和沉积厚度变化，建立了晚新生代沉积模式，所取得的研究成果可为南海油气的进一步勘探开发提供有效的基础资料。     

吉林省煤层气资源赋存的地质特征分析

通过对吉林省煤层气的地质特征分析可以看出,煤层气藏的形成是多种地质因素共同作用的结果,它在时空上的分布和区域构造、沉积环境、含煤岩系的岩性组合密切相关。煤层气聚气区多分布在成煤条件相对好的地区,而含煤盆地的沉积类型则控制着聚气带在盆地内的展布。冲积平原类型的含煤盆地,聚气带多发育在远离河道的河流沉积旋回的上部,而山间湖泊类型的含煤盆地,聚气带则发育在山麓相前缘的湖相泥岩上下。长春煤田、辽源煤田和通化煤田是开发利用煤层气资源最有利的首选地区。     

红阳煤田的岩煤层对比

采用岩相旋回法、标志层法和煤岩层组合特征等多种方法,对红阳煤田的岩煤层进行综合对比,认为该煤系沉积稳定,标志层明显,易于辨认及对比,岩性、岩相变化有一定规律可循,具有比较明显的旋回结构,煤层层位在旋回上有一定的分布规律,为一套海陆交互相滨海平原型沉积。     

重庆市沥鼻峡背斜盐井矿区龙潭组沉积特征及聚煤规律

通过对重庆市沥鼻峡背斜盐计矿区含煤地层研究，探讨了矿区龙潭组的沉积特征和聚煤规律，得出矿区龙潭组为泻湖-海湾-潮坪沉积体系，成煤时期的不同沉积环境，聚煤沉降幅度小，沉积速度和物质补偿均衡，有利于泥炭堆积，因此矿区含煤层数、煤层厚度较稳定，该区处于华蓥山潮坪地带，是龙潭期聚煤中心之一。     

Zircon U–Pb Ages and Lu–Hf Isotope of the Dongchuan Group in Central Yunnan, China, and their Geological Significance

On the southwestern margin of the Yangtze Block, the Dongchuan Group consists of slightly metamorphosed sedimentary rocks, including silty slate, argillaceous slate, clayey slate, arkose, dolomite, and minor volcanic rocks. To date, it is still a controversy over the depositional age and stratigraphic sequence of the Dongchuan Group. In this study, we analyzed five samples of meta-sedimentary rocks and one sample of meta-tuff from the Yinmin, Luoxue and Etouchang Formations of the Dongchuan Group in the Yuxi region for detrital zircon U-Pb ages and Lu-Hf isotope. The detrital zircon ages of the meta-sediments vary from 3073 to 1703 Ma, mainly clustered at three periods, from 1889 to 1840, 2490 to 2008 and 2878 to 2844 Ma. The youngest age peak of all the samples is ～1859 Ma, with the εHf(t) values of the zircons ranging from-20.3 to +4.3 and more than 90% being negative, indicating that the Paleoproterozoic crustal accretion on the southwestern margin of the Yangtze Block was dominated by reworking of the ancient crustal materials involved in the assembly and breakup of the Columbia supercontinent. Another important age range is between 2490 Ma and 2008 Ma, with εHf(t) values from-14.7 to +8.9 and 70% of them are negative, suggesting that the magmatism in the source area was also dominated by reworking and recycling of the ancient crustal materials, with minor juvenile mantle substances added. The detritus was probably derived from the Paleoproterozoic crystalline basement in the southern Yuxi region. The oldest peak age is ～2847 Ma and the εHf(t) values are from-7.7 to +7.0 with 50% of both positive and negative values, demonstrating a possible ～2.85 Ga ancient continental nucleus on the southwestern margin of the Yangtze Block and substantial growth in juvenile crust materials during this period. Besides, the weighted average age of the zircons from the meta-tuff of the Etouchang Formation is 1677 ± 14 Ma. Combining the previous research data and this study, we can constrain the depositional age of the Dongchuan Group in central Yunnan Province to the period from the late Paleoproterozoic to early Mesoproterozoic, slightly earlier than that of the Dongchuan Group in the Dongchuan area near to the southwestern Sichuan Province. The depositional age of the Dongchuan Group is older than that of the Kunyang Group.